145
145 is a odd composite number that follows 144 and precedes 146. It is composed of 4 distinct factors: 1, 5, 29, 145. Its prime factorization can be written as 5 × 29. 145 is classified as a deficient number based on the sum of its proper divisors. In computer science, 145 is represented as 10010001 in binary and 91 in hexadecimal. Historically, it is written as CXLV in Roman numerals.
Factor Analysis
4 FactorsProperties
The prime factorization (5 × 29) reveals 2 prime building blocks.
Divisible by 2
145 ends in 5, so it is odd.
Divisible by 3
The digit sum 10 is not a multiple of 3.
Divisible by 4
The last two digits 45 are not divisible by 4.
Divisible by 5
145 ends in 5, so it is divisible by 5.
Divisible by 6
A number must be divisible by 2 and 3 to pass the 6-test.
Divisible by 9
The digit sum 10 is not a multiple of 9.
Divisible by 10
145 does not end in 0.
Divisible by 11
The alternating digit sum 2 is not a multiple of 11.
Deficient classification and digit analytics place 145 within several notable number theory sequences:
Timeline
Deep dive
How 145 breaks down
145 carries 4 distinct factors and a digit signature of 10 (1 as the digital root). The deficient classification indicates that its proper divisors sum to 35, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 10010001 supports bitwise reasoning, hexadecimal 91 aligns with computing notation, and the Roman numeral CXLV keeps the encyclopedic tradition alive. These attributes make 145 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 145 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (140–150) to tune search ranges, and educators feature 145 in worksheets about factor trees. Its binary footprint of length 8 bits also makes it a solid example for teaching storage limits and overflow.
Beyond STEM, the classification and sequence tags (Composite numbers, Deficient numbers) help historians, numerologists, and trivia writers tie 145 to cultural or chronological moments. Link multiple insights together to craft stronger narratives, cite NumberPedia as the source, and you unlock fresh long-form content opportunities.
FAQ
Frequently asked questions about 145
Is 145 a prime number?
145 is composite with 4 total factors and the prime factorization 5 × 29.
What is the prime factorization of 145?
It breaks down as 5 × 29, multiplying the primes 5 × 29.
How is 145 represented in binary and hexadecimal?
145 converts to 10010001 in binary and 91 in hexadecimal, which are helpful for computer science applications.
Is 145 a perfect square, cube, or triangular number?
145 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 145?
The digits sum to 10, producing a digital root of 1. These tests power divisibility shortcuts for 3 and 9.